This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 16 |
| 4 | 53 |
| 5 | 206 |
| 6 | 817 |
| 7 | 3620 |
| 8 | 16361 |
| 9 | 80218 |
| 10 | 401501 |
| 11 | 2139512 |
| 12 | 11641885 |
| 13 | 66599846 |
| 14 | 388962953 |
| 15 | 2367284236 |
| 16 | 14700573137 |
| 17 | 94523836850 |
| 18 | 619674301621 |
| 19 | 4186249123808 |
| 20 | 28809504493061 |
| 21 | 203556335785342 |
| 22 | 1463877667140065 |